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Diffstat (limited to 'docs/misc/arm/early-printk.txt')
-rw-r--r-- | docs/misc/arm/early-printk.txt | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/docs/misc/arm/early-printk.txt b/docs/misc/arm/early-printk.txt new file mode 100644 index 0000000000..4065811e82 --- /dev/null +++ b/docs/misc/arm/early-printk.txt @@ -0,0 +1,14 @@ +How to enable early printk + +Early printk can only be enabled if debug=y. You may want to enable it if +you are debbuging code that executes before the console is initialized. + +Note that selecting this option will limit Xen to a single UART definition. +Attempting to boot Xen image on a different platform *will not work*, so this +option should not be enable for Xens that are intended to be portable. + +CONFIG_EARLY_PRINTK=mach +where mach is the name of the machine: + - vexpress: printk with pl011 for versatile express + +By default early printk is disabled. |